Project Summary/Abstract This Program Project takes a comprehensive approach to investigating dengue virus (DENV) transmission within a family setting (Project 1), defining the early immune response to DENV and its correlations to outcomes (Project 2), and investigating immune responses in DENV vaccine recipients (Project 3). These projects include studies with distinct experimental designs with two large prospective cohorts conducted in two countries (Thailand and the Philippines). This complex and integrative research effort will be supported by a laboratory core (Core C) which will provide high quality laboratory support for specimen processing, management, and routine clinical and dengue diagnostic laboratory testing. The Clinical Research Laboratory Core (Core C) consists of 3 facilities: a) AFRIMS-Virology laboratory in Bangkok, Thailand (Core C-BKK), b) AFRIMS-Virology laboratory in Kamphaeng Phet (Core C-KPP), Thailand, and c) AFRIMS-Virology laboratory in Cebu, the Philippines (Core C-Cebu). Core C-BKK has been conducting research in Southeast Asia and nearby regions for over 50 years and has served as a reference laboratory for flavivirus diagnosis; it will serve as the administrative and logistics center for laboratory activities and will be the main laboratory for serologic diagnosis and for study-specific specialized tests. Core C-KPP will be the main facility for specimen processing for Projects 1 and 2; it will also serve as a molecular diagnostic laboratory and perform research laboratory testing including assessment of viral burden and analysis of immune responses by flow cytometry and antigen and antibody assays. Core C-Cebu is currently the main specimen processing facility for samples collected from dengue vaccine study subjects in Project 3. The Core Laboratory will be the center for specimen storage, inventory, and distribution. The Core Laboratory has a secure and accountable inventory system that has facilitated sample distribution to diagnostic and research laboratories. Since the beginning of the Program Project, the Core Laboratory has processed and managed specimens including plasma/serum, cryopreserved PBMC, and RNA from PBMC. These samples have been used for functional antibody assays, assays for biological mediators, and molecular and proteomic analyses that have been published and contributed to current understanding on many aspects of dengue. Study-specific quality management plans have been established and the laboratory?s operation is audited quarterly for specimen chain custody, specimen handling, and sample accountability.